Contact angle and inertia effects on the instability of partially wetting liquid rivulets. Finite Element analysis

SEBASTIÁN UBAL; PAUL GRASSIA; DIEGO M. CAMPANA; MARÍA D. GIAVEDONI; FERNANDO A. SAITA

San Diego

Simposio; 17th International Coating Science and Technology Symposium (ISCST 2014); 2014

International Society of Coating Science and Technology / Association of International Metallizers, Coaters and Laminators

We study numerically the stability of a thread of fluid deposited on a flat solid substrate by solving the full 3D Navier-Stokes equations. A good agreement is observed between our results and predictions from linear stability analysis obtained by other authors. Moreover, we also analysed the influence of inertia for different contact angles and found that inertia strongly affects the growth rate of the instability when contact angles are large. Our finite element analysis allows us to follow the evolution of the free surface instability until comparatively late stages, where the filament begins to break into droplets. The rupture pattern observed for several cases shows that the number of principal droplets agrees reasonably well with an estimation based on the fastest growing modes.